Activation of actin‐containing microfilaments by vasopressin in the amphibian urinary bladder epithelium: A fluorescent study using NBD‐phallacidin

Abstract

The effect of an antidiuretic hormone (ADH, vasopressin) on the microfilament system of the toad urinary bladder lumenal epithelium was investigated using NBD-phallacidin (NBD-ph). The latter material is a specific fluorescent label for F actin. In the presence of an osmotic gradient, both ADH and cyclic adenosine monophosphate (cAMP) appear to induce the polymerization of monomeric actin into F actin-containing microfilaments. The latter may then be involved in the morphological changes, including the formation of lateral intercellular lakes, associated with the typical hydroosmotic response.

Wheat germ agglutinin (WGA) reduces ADH-induced water flow and induces cell surface changes in epithelial cells of frog urinary bladder

“…As mentioned earlier and shown here ( Fig. 7), apical cytoskeleton in amphibian bladder is dense and highly organized [9,20,31,32,33] and the actin-containing filaments could be associated with both plasma membrane glycoproteins and cytoplasmic organelles, including aggrephores and cortical granules.…”

“…The importance of cytoskeleton integrity for the hydrosmotic response to ADH has been well documented [9,15,20,34]. Its precise role, however, is not clear.…”

“…Its precise role, however, is not clear. It has been proposed, for example, that ADH triggers the polymerization of monomeric actin in actin F and the alignment of the microtubules and filaments running just below the luminal membrane [9,10,34]. Binding of apical cytoskeleton to the plasma membrane and to aggrephores is maintained when aggrephores fuse with the membrane.…”

Double Staining of F-Actin and Mg2+, Ca2+-ATPase in Rat Hepatocytes by NBD-Phallacidin and Enzyme Histochemical Techniques.

“…Therefore, of special interest is to analyze the relationship between the two in secreting and non-secreting hepatocytes. In the present study, NBD-phallacidin (NBD-ph) -fluorescence (1,2) and enzyme histochemical techniques have been successively combined to demonstrate F-actin and Mg2+, Ca2+-ATPase (ATPase) activity associated with the bile canalicular system in the same preparation.…”